Blank forging machine



Jan. 11, 1944- R. G. LE TOURNEAU BLANK F'ORGING MACHINE Filed Jan. 31, 1942 5 Sheets-Sheet 2 INVENTOR O RGYLeY'ourn eau,

1944- R. G. LE TOURNEAU BLANK FORGING MACHINE Filed Jan. 31, 1942 &

R N o v Q O O I E,"

I'll "I I a I 3 SheetsSheet 3 IN VENTOR HTTYS Patented Jan. 11, 1944 BLANK FORGING MACHINE Robert G. Le Tourneau, Peoria, 111., assignor to R. G. Le Tourneau, Inc., a corporation Application January 31, 1942, Serial No. 429,124

11 Claims.

This invention relates to the metal forging art, and particularly to the forging of a hollowed-out blank from a solid billet of hot metal.

I have particularly in mind the forging of blanks for ordnance shells, and the principal object of my invention is to provide a machine and method by means of which a billet may be pierced or penetrated to a predetermined depth by the advance of a plunger, and then without any halt in the movement of the plunger, the plunger and billet will be advanced as a unit and the latter passed through forming rolls which roll the hot metal about the plunger as a mandrel, until a shell blank is formed which will be of a predetermined external diameter and length, which remains solid or closed at one end only, and which end will be of a predetermined thickness.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawingssimilar characters of reference indicate corresponding parts in the several views:

Figure 1 is a fragmentary plan, partly in section, of my improved blank forming machine, showing the billet piercing plunger fully retracted. I

Figure 2 is a similar view showing the billet pierced, and just as the billet is being released for advancing movement with the plunger.

Figure 3 is a similar view showing the plunger and pierced billet as advancing between the forming rolls.

Figure 4 is a fragmentary side elevation of the machine to show the release means for the billet holding head.

Referring now more particularly to the characters of reference on the drawings, the machine comprises a base I on which is mounted an elongated housing 2 containing at one end a guide bearing 3 for the main plunger 4 and at the other end a tubular open-ended holder 5 for the cylindrical billet 6 to be forged. The housing is open ahead of the holder as at I for the insertion of the billet.

A piercing plunger 8, whose size, length and general configuration conform to the desired shape of the interior of the blank to be forged, is secured on and projects from the plunger 4 toward the billet, being spaced therefrom sufll- "shaped arm I I.

be described later.

ciently to clear the opening! when the plunger is fully retracted as shown inFig. 1.

Beyond the housing 2, a plurality of pairs of concave forming rolls 9 are mounted on the base, these rolls being disposed in alternating relation at right angles to each other as shown, and forming a continuous bank disposed symmetrical to the axis of the plunger. It is of course understood that the rolls are arranged to gradually decrease the diameter of the billet advanced therebetween until the initial diameter of the billet is reduced to the desired extent and it becomes correspondingly elongated.

The end of the holder 5 nearest the rolls is in-' itially closed by a head [0 mounted on the outer end of the short leg of a horiontally disposed L- Said short leg extends radially of the holder to the exterior of the housing'while the long leg extends along one side of the housing away from the rollsand is pivoted at its outer end as at I2 on and between brackets l3 mounted rigid with the housing. I

Between the pivot l2 and the short leg of the arm, the long leg is pivotally connected to one end of a toggle linkage. H which at its other end is pivoted on the brackets 13. The linkage is arranged so that whenthe head is in a closing or billet retaining position',fit,i's just beyond .a'dead center position substantiallyat right angles to the long leg of arm H, and is then prevented from further movement in a corresponding direction by suitable releasing stop means which will The linkage is moved to its dead center position so that the arm II will be swung and the head held against the billet, by means of an air cylinder I5 swivelly mounted in fixed connection with the base i and having a piston rod l6 projecting therefrom and pivotally connectedto one of the links. Control of the air into and from the cylinder is effected by a manual two-way valve l'l interposed in the air sup ply line Ha.

A heavy compression spring (8, disposed and supported at one end in a housing 19 secured on one bracket I3, is connected at its other end to arm I l by a cable 20 or the like. The spring and cable are arranged relative to the arm so that when the arm head is in a billet engaging position and the linkage is at dead center, the spring is strongly compressed or cooked.

When a billet is initially in place in the holder and the plunger is retracted, air is admitted to the cylinder to move the linkage l4 to the neothen under compression, as previously stated, holding the linkage in said position.

In order to prevent further movement of the linkage past dead center due to the pull of the spring, and to cause the linkage to be initially broken when the held billet has been pierced to. the desired depth, the following arrangement is provided:

The central connecting pivot pin 2| of linkage i4 when the latter is in dead center position, depends into the path of movement of and is then engaged by the upper end of an upstanding lever 22 pivoted in a fixed position at its lower end. The lever engages the pin behind or on the side opposite the direction of breaking movement of the linkage, and said lever is in turn engaged on its opposite side by a stop 23 on the adjacent bracket l3. A push rod 24 is connected to the lever and extends thence rearwardly and parallel to the plunger 4 to a termination overlapping the carriage 25 disposed beyond housing 2 and on which the plunger is fixed/for movement therewith.

At its rear'end, rod 24 is supported by a depending link 26, and when lever 22 is tially vertical and engaged with pin 2|, said rear end of the rod is in position to be engaged by a lug 21 fixed on and projecting from the carriage. When the carriage and plunger are fully retracted, lug 21 is disposed behind rod 24 a predetermined distance so it will not engageihe rod until the carriage has advanced sufficiently to cause the plunger to penetrate the billet to the desired depth, substantially as shown in Fig. 2.

1e exact amount of advance before such engagement is effected may be altered somewhat by reason of a longitudinally adjustable unit 24a which forms part of rod 24.

When the lug. engages the rod, a further short advance of the carriage then causes lever 22 to also advance and push pin 2| so that the dead center position of linkage I 4 is broken.

Spring l8 then instantly acts to swing arm II so that head ill will clear the billet.

Link 26 is relatively short and is vertical when the lever engages pin 21,; so that when the lever swings forward with a push on the rod, link 26 will be lowered sufliciently to also lower the rear end portion of the rod and allow the lug 21 to move over the same, as indicated in'Fig. 4. The lever 22 is returned to a stop engaging position upon the return of the carriage to a fully retracted position,fby means of a rigid finger 28 depending fI'OII l the carriage ahead of lug 21 and engageable with a stop 29 projecting from one side of the rod.

In operation therefore the plunger 4, which is at least as long as the bank of rolls, is advanced by suitable power means applied to the carriage so that the piercing plunger and mandrel 8 will penetrate the billet 6 to a given predetermined depth, as shown in Fig. 2.. The vhead Ill at this time prevents advancing movement of the billet, since thejiead is held against movement by reason of the dead center position of the control linkage, .As soon as such penetration is effected,

substanthe linkage is immediately broken or collapsed,

as previously described, pulling the head clear of the path of the billet and allowing the latter to advance with the plunger and without any further penetration of the billet. Such further advance of the plunger passes the billet between the rolls 9 so that the latter act in the usual manner to effect a combined reduction of diameter and elongation of the billet so that the metal becomes rolled about the plunger 8 as a mandrel and a forging 6a is formed which gradually assumes the shape and size desired-for the shell blank.'

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as "do not form a departure from the spirit of the invention, as definedby the appended claims.

Having thus described myinvention, what-I claim as new and useful and desire to secure by Letters Patent, is:

l. The method of forging a blank from a solid billet with the use of a piercingv plunger. comprising as a continuous operation the steps of initially holding a heated billet" against movement, advancing the plunger into the held billet to form a cavity of predetermined depth therein, releasing the 'billet without halting the advance of the plunger, whereby the billet and 'plungerwill then advance as a unit, and passing the advancing unit through forming rolls.

2. A blank forming machine comprising a cornbination plunger and mandrel, means mounting theplunger for axial movement, a tubular, openended billet holder mounted in the path of advancing movement of the plunger, a bank of forming rolls beyondthe holder disposed symmetric with the extended axis of the plunger,

'means initially holding the billet against advance from the holder whereby upon advance of the plunger a predetermined distance from its initial position the billet will be pierced to a predetermined depth to form a cavity therein, and means etorelease the holding nieans from the billet when the latter has been pierced to suchg depth, and without halting advance of said plunger moving means, whereby th billet and plunger then advance as a unit t pass the billet'through the forming rolls.

3. A blank forming machine comprising a combination plunger and mandrel, means mounting the plunger for axial movement through a stroke of predetermined length from an initial position; a tubular, open-ended billet holder mounted in the path of advancing movement of the plunger, a head normally closing the holder at the end thereof opposite the plunger whereby the billet is held from advancing from the holder with pressure of the plunger thereagainst, means mounting the head for movement from a closing position to one clear of the path of movement of the billet, means to move the head to a closing position, a, power element connected with and tending to move the head clear of the billet. releasable means initially holding said element from. functioning, the plunger, upon advance from its initial position to a predetermined point intermediate the ends of its stroke, piercing the billet to a predetermined depth; and means bee tween the plunger and holding means to release of the plunger at said advancing from the holder with pressure of the plunger thereagainst, a pivoted arm on which the head is mounted arranged to allow the head to swing laterally of the path of advancing movement of the plunger and clear of the billet, toggle linkage connected at one end to the arm and disposed substantially at dead center position when the head is in a closing position, and control means to break the linkage and pull the arm to move the head to a billet clearing position. 7

5. A structure as in claim 4, in which the arm is of L-shaped form with the head on the outer end of one arm and the pivot at the outer end of the other arm; said one arm extending radially of the axis of the plunger and said other arm extending substantially parallel to said axis in the direction from which the plunger advances, the toggle linkage being connected to said other arm of the leg and being substantially at right angles thereto when in dead center position.

6. A blank forming machine comprising a combination plunger and mandrel, means mounting the plunger for axial movement, a tubular, open ended billet holder mounted in the path of advancing movement of the..p1unger, a head normally closing the holder at the end thereof opposite the plunger whereby the billet is held from advancing from the holder with pressure of the plungerthereagainst, a pivoted arm on which the head is mounted arranged to allow the head to swing laterally of the path of advancing movement of the plunger and clear of the billet, toggle linkage connected at one end to the arm and disposed substantially at dead center position when the head is in a closing position, means to move the linkage to said position, means tending to break the linkage but held in restraint by the dead center positioning of the linkage and means acting directly on the linkage to break the same and functioning upon advance of the plunger a predetermined distance from a fully retracted position.

I 7. A structure as in claim 6 in which said last named means includes, with a pin projecting at right angles to the linkage from intermediate the ends thereof, a lever pivoted in a fixed position and normally in a position to engage the pin on its rear side to move the same in a linkage breaking direction upon swinging of the leverin the direction of advancing movement of the plunger. a push rod extending rearwardly from the lever substantially parallel to the plunger and 9. lug rigid with the plunger behind the rod to engage the rear end of the same.

8. A structure as in claim 6 in which said last named means includes, with a pin projecting at right angles to the linkage from intermediate the ends thereof, a lever pivoted in a flxd position and normally in a position to engage the pin on its rear side to move the same in a linkage breaking direction upon swinging of the lever in the direction of advancing movement of the plunger, a push rod extending rearwardly from the lever substantially parallel to the plunger and 9. lug

rigid with the plunger behind the rod to engage the rear end of the same, and means supporting the rod at its rear end so that after a short longitudinal advancing movement the rear end portion of the rod will move clear of the lug to enable the latter to advance beyond said rear end portion of the rod.

9. A structure as in claim 6 in which said last named means includes, with a pin projecting at right angles to the linkage from intermediate the ends thereof, a lever pivoted in a fixed position and normally in a position to engage the pin on its rear side to move the same in a linkage breaking direction upon swinging of the lever in the direction of advancing movement of the plunger, a push rod extending rearwardly from the lever substantially parallel to the plunger and a lug rigid with the plunger behind the rod to engage the rear end of the same, and means between the plunger and rod to retract the latter and restore the lever to said normal position upon return of the plunger to a fully retracted position.

10. A blank forming machine comprising a combination plunger and mandrel, means mounting the plunger for axial movement, a tubular,

" open-ended billet holder mounted in the path of advancing movement of the plunger, a head normally closing the holder at the end thereof opposite the plunger whereby the billet is held from advancing from the holder with pressure of the plunger thereagainst, means mounting the head for movement from a closing position to one clear of the path of movement of the billet, means to move the head to a closing position, a spring connected with and tending to move the head clear of the billet, releasable means initially holding said spring from functioning and means functioning to release the holding means upon advance of the plunger and after the latter has pierced the held billet to a predetermined depth.

11 A blank forming machine comprising a combination plunger and mandrel, means mounting the plunger for axial movement through a stroke of predetermined length from an initial position, a tubular, open ended billet holder mounted in the path of advaning movement of the plunger, means initially holding the billet against advance from the holder whereby upon advance of the plunger from its initial position to a, predetermined. point intermediate the ends of its stroke the billet will be pierced to a predetermined depth to form a cavity therein, means between the plunger and the holding means to release the latter upon arrival of the plunger at said point in its stroke whereby the plunger when advancing beyond said point will likewise advance the billet, means included with said last named means to alter the extent of advancing movement of the plunger necessary before re lease of the holding means will be effected whereby to alter the position of said point in the plunger stroke relative to the ends of the stroke.

ROBERT G. LE TOURNEAU. 

